Two subtypes of schizophrenia are proposed: early onset male schizophrenics characterized by poor premorbid history, little affect and poor long-term outcome; late onset female schizophrenics characterized by good premorbid history, prominent affect and good long-term outcome. It is hypothesized that neural dysfunctions are particularly characteristic of schizophrenia in men and may be important in the further delineation of subgroups to reduce intragroup heterogeneity in schizophrenia. To test this, 100 DSM- III R schizophrenic patients will be divided into sex by onset age groups and assessed for brain anatomic abnormalities (using magnetic resonance imaging), psychoneurological impairment (both lateralized and interhemispheric transfer deficits), and psychiatric symptoms (positive and negative). Emphasis will be on the corpus callosum, lateral ventricles and frontal cortex. It is generally expected that early onset male schizophrenics will evidence the most structural abnormality and performance impairment, both of which will be associated with negative symptoms. This study will help elucidate the nature of sexual dimorphism in brain structure, the relationship between structural size and shape variation and function, and the role of neural deviation in the further refinement of schizophrenia subtyping.